Antivirus software is a program that protects your computer from harmful software called viruses and malware. Just as your body's immune system fights off germs that try to make you sick, antivirus software watches for dangerous programs that try to damage your computer, steal your information, or spy on what you're doing.

When you download a file or visit a website, antivirus software scans it to check if it's safe. If it detects something suspicious, it blocks the threat and warns you, much like a guard checking everyone who enters a building. The software keeps a constantly updated list of known threats, similar to how doctors track new strains of flu.

Computer viruses got their name because they spread from one computer to another like biological viruses spread between people. A virus might sneak onto your computer through an email attachment, a downloaded game, or a suspicious website. Without antivirus protection, these programs could delete your files, slow down your computer, or record your passwords.

Most computers and phones today come with built-in antivirus protection that runs quietly in the background, updating itself regularly to recognize new threats. Keeping your antivirus protection active and updated helps keep your digital information more secure.